Learning disabilities share common defects

A study of two models of intellectual disability in mice has found that they share similar disease mechanisms.

Researchers found that treatment with a statin drug called Lovastatin - commonly used to treat high cholesterol - can correct high levels of protein production in the brain linked to the conditions.

The findings suggest that different types of intellectual disabilities may benefit from common therapeutic approaches, the researchers say.

Studies of people with learning disabilities have identified a wide range of genetic causes. Around a third of people affected also have symptoms of autism spectrum disorders, suggesting that the mechanisms underlying these conditions may be shared.

Researchers studied mice with a genetic mutation that means they produce lower levels of a protein called SynGAP. The mice show learning and behavioral difficulties and act as a model system to understand why people with mutations in the human version of the gene suffer from intellectual disability.

The team found that treatment with Lovastatin normalized levels of protein production in the brains of the mice. Their results suggest that Lovastatin acts by reducing levels of the active form of a protein called ERK1/2.

They compared their findings with mice that lack a protein called FMRP, which also causes cellular and behavioral changes that can be rescued with Lovastatin. Loss of FMRP in people leads to Fragile X Syndrome, the most common inherited form of intellectual disability and autism.

Further research is needed to determine whether the treatment can restore learning and development in people.
The study is published in the Journal of Neuroscience.